1. Field of the Invention
The present invention relates to a printed wiring board having solder pads for connection with an electronic component or an external substrate and to a method for manufacturing such a printed wiring board.
2. Discussion of the Background
Japanese Laid-Open Patent Publication H04-320093 describes a pad (fourth pad 14) made up of circular conductor (14-2), slit 8 surrounding conductor (14-2) and annular conductor (14-1) surrounding the slit (see FIG. 2). Conductor (14-1), which is part of the pad, is connected to first pad 11 by a surface pattern. Then, first pad 11 is connected to first inner-layer pattern 21 by surface pattern 17 and a via conductor. On the other hand, conductor (14-2), which is part of the pad, is connected to third inner-layer pattern 23 by a via conductor. Fourth pad 14 simplifies the modification process when switching input/output signals. For example, first pad 11 and the first inner-layer pattern are electrically continuous at first. At that time, conductor (14-1) and conductor (14-2) are not electrically continuous. When the circuit network is required to be modified, surface pattern 17 is cut off, and conductor (14-1) and conductor (14-2) are connected by stud bump 6. Accordingly, first pad 11 is connected to the third inner-layer pattern instead of the first inner-layer pattern, and switching input/output signals is completed. The contents of this publication are incorporated herein by reference in their entirety.